1. Field of the Invention
The present invention relates to a medical instrument sterilizing and washing method and apparatus capable of easily sterilizing and washing medical instruments in a short time without corroding the medical instruments and in particular, even medical instruments such as endoscopes and the like which are composed of the combination of metal, resin and the like, formed to a complex shape, directly used in a living body and greatly contaminated with dirty materials and germs.
2. Description of the Related Art
Conventionally, medical instruments and in particular, endoscopes and the like which are directly used in a living body are contaminated with blood and body fluid and further very liable to be contaminated with various types of germs. Accordingly, they must be sterilized and washed each time they are used.
A most effective prior art method of sterilizing and washing the medical instruments is heat sterilization and has been widely used up to now. Recently, however, there has been an abrupt increase in the number of medical instruments such as the endoscopes and the like which are composed of resin, rubber and the like in addition to metal. Since these medical instruments employing resin, rubber and the like cannot be subjected to heat sterilization, they are sterilized and washed with a glutaaldehyde antiseptic solution.
However, since glutaaldehyde antiseptic solution is a powerful medicine, sterilizing and washing using it presents certain problems such as; the glutaaldehyde antiseptic solution affects the skin affection and lungs of a worker who performs washing with it when he comes into contact with and inhales the liquid medicine; since post washing is necessary to wash the liquid medicine away after completion of the sterilizing and washing, a long time is necessary for a sterilizing processing; a sufficient sterilizing effect cannot be achieved against germs, viruses and the like which are resistant to gluta aldehyde antiseptic solution; and hospital contamination may be caused in a worst case.
There has been proposed using as an antiseption solution electrolytically-generated super-acidic water with strong acidity which is generated by electrolyzing water in which sodium chloride is dissolved. See Japanese Unexamined Patent Publication No. 7-275811, Japanese Unexamined Patent Publication No. 9-66064 and Japanese Unexamined Patent Publication No. 9-108307.
Since of using electrolytically-generated strongly acidic water has no adverse affect to the operator and does not require post washing, time and manpower necessary for sterilization processing can be reduced. A problem, however, with using electrolytically generated strongly acid water as the sterilizing solution is that the metal constituting a medical instrument to be washed, for example, stainless steel such as SUS 304 and the like which is often used to form medical instruments is corroded by electrolytically-generated strongly acidic water. When the electrolytically-generated strongly acidic water is used under conditions that the pH thereof is increased by dilution or the like or the concentration of residual chlorine is lowered by lowering the concentration of additive sodium chloride to lower the corrosion caused by the strongly acidic water, there arises a problem that a sufficient sterilizing capability cannot be obtained and/or a longer processing time is required.
An object of the present invention is to provide a medical instrument sterilizing and washing method and apparatus capable of sterilizing and washing medical instruments with a high sterilizing capability in a short time without corroding the metal of the medical instrument being washed.